Askar F3.9 0.7x Full-frame Reducer Professional Astronomical Accessory Dedicated for FRA400C Astrograph
Description:
- Specially designed for the FRA400C, this 0.7x reducer adopts a triplet lens design, it can reduce the overall focal length to 280mm and the focal ratio to F3.9 while providing a flat-field correction. When used with the reducer, the FRA400C supports full-frame imaging and the back focus is a standard 55mm.
- The shorter focal ratio enables the telescope to achieve a wider field of view and faster exposure times, making it ideal for shooting large nebulae, star clusters, as well as faint and fast-moving celestial objects.
- The FRA400C reducer features an M48x0.75 rear-end adapter and has a built-in 2-inch filter thread for convenient filter attachment.
Specification:
- (After attaching) FRA400C Focal length: 280mm
- (After attaching) FRA400C Focal ratio: f/3.9
- Lens Number: Triplet design
- Back Focus: 55mm (from the base of M48 male thread)
- Weight: 0.46kg
- Rear-end thread type: M48x0.75 (M48x0.75 filter thread inside)
Package Included:
- 1 x Reducer


